The present invention relates to electromagnetic (EM) shielding in computer systems. In particular, the invention relates to the physical attachment of an EM shielding cage to a circuit board and further to the electrical connection of an EM shielding cage to a desired voltage level.
Shielding cages can be provided in computer systems for providing electromagnetic shielding for components of the computer system such as a microprocessor. Where the component to be shielded is mounted upon a circuit board in the computer system, the shielding cage can be mounted upon the circuit board. The shielding cage can also be electrically connected to a predetermined voltage level (for example an earth voltage) so as to facilitate effective shielding. This can be achieved by means of a springy leg on the shielding cage that can contact a grounded pad on the circuit board, when the shielding cage is sandwiched between a heatsink and the circuit board.
However, with such an arrangement, the positioning of the springy legs is not well controlled and can be problematic, particularly in dense circuit board layouts. Also, the shielding cage is not firmly located whereby poor thermal contact between the heatsink and components of the computer system can result, leading to potential thermal failure.